No picture visible here. As mentioned, the electrochemical method is very gentle, so it will not harm the bell. Are you certain there is nothing on the bell that prevents the vinegar from working? I cleaned up a large bronze bilge pump some years ago, and it required a lot of work as there was a lot of oil on it that helped preserve the tarnish.

I have all these items in the car during winter here in Norway, and som additional ones.Snow chains. Got me home safely more than once.Some strong, thin rope and a knife. If a link breaks in the snow chains, this is very handy to have.